Overview on the welding technologies of CLAM steel and the DFLL TBM fabrication

•The weldability on CLAM steel by different welding methods such as HIP, TIG, EBW and LBW and the properties of as-welded and post-weld heat-treated joints were reviewed.•The welding schemes and the assembly strategy for DFLL-TBM fabrication were raised.•Many tests and research efforts on scheme feasibility, process standardization, component qualification and blanket assembly were carried out.